Actions

Multiattack

The Bog Octopus makes two Melee Tentacle Attacks.    

Tentacles

Melee Weapon Attack: +6 To Hit, Reach 15ft, One Target. Hit: 14 (3D6+4) Bludgeoning Damage. If the Target is a creature, It is Grappled (Escape DC 17). Until this Grapple ends, the target is Restrained, and the octopus can't use that tentacle on another target. The Bog Octopus has six tentacles.      

Mud Cloud (Recharges on a D6 Roll of 5-6):

A 20-Foot-Radius Cloud of mud extends all around the octopus if its underwater. The area is heavily obscured for 1 minute, although a significant current can disperse the mud. After releasing the mud, the octopus can use the Dash Action as a Bonus Action.